UNIT OF MEASURE USED in the construction of the school (data taken from the Manuel Ángel Feal Antelo study). Freire Tellado has previously investigated the unit of measurement in the school. Comparing the measurements described in the historical documents with those taken in the building, 3 possible values for the foot are obtained:
a) 281.27 mm
b) 296.06 mm and
c) 282.222 mm.
In the end, based on other verifications, the next foot value used in the construction of the Cardinal’s school was chosen.
Unit Multiple Submultiple
Units School pie vara 1/2 * -1/3 -1/4 -1/8 – 1/16
Centimeters 28.22 cm 84.66 cm 14.11 -9.41 -7.06 -3.52 -1.76
This study should be taken with caution, since different stonemasons who were successful at work may have used different measures. Even so, the unit has proven to be consistent in later studies. There are some coincidences with the rules given by Palladio, Simón García and Fontana. In the book by Andrea Palladio I Quattro Libri dell’Architettura (1570) includes the descriptions and drawings of several ancient domes. It follows that Fontana from the drawings of Palladio established a rule of 1/9 for the thickness in the starts.
The dome of the College coincides with two of the rules of Palladio. The first coincidence is the thickness of the starts. In the School, the maximum light is 36m and the outer radius is 44m. The difference between the corresponding radios is 4 feet, which means 1/9 of the section.
The foot of today: If we move by the information that is given today about the size of the foot unit, we find this definition “The foot is a unit of length of artificial origin, based on the human foot, already used by civilizations ancient.” To measure the length, in almost all the world the meter is used, except in Anglo-Saxon countries such as the United States, Canada and the United Kingdom, which is usually used the foot. The exception is in aeronautics, in which the height is still measured in thousands of feet in almost all countries. The equivalence to meters is the following:
1 current foot = 30.48 centimeters = 0.3048 meters
1 meter = 3.2808 feet
The Roman foot, or pes, was equivalent, on average, to 29.57 cm; the Carolingian foot, formerly called the Drusian or Drusian foot -pes drusianus-, was equivalent to nine eighths of the Roman, that is, approximately 33.26 cm; and the Castilian foot was equivalent to 27.8635 cm.